Gas control system

ABSTRACT

An apparatus includes a high-pressure tank, a controller, a valve, controlled by the controller, and a heater.

BACKGROUND

Natural gas end-users occasionally use high-pressure tankers to providenatural gas into their system. This will happen when there is a shortageof natural gas within the system to meet the demand or the end-user doesnot have a connection to an existing pipeline. Commercially,high-pressure natural gas tankers operate at pressures over 4,000 PSIGwhen initially filled and become depleted with lower pressure (e.g.,less than 100 PSIG) when natural gas is supplied to the end-user. Theactual supply pressure depends on the end user's requirements. Existingsystems do not provide an efficient and safe control system with 100%redundancy while also ensuring lower costs.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram of an example environment in which systems and/ormethods described herein may be implemented;

FIGS. 2A and 2B are schematic diagrams of a process;

FIG. 3 is an example flowchart;

FIG. 4 is an example diagram; and

FIG. 5 is a diagram of an example computing device.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The following detailed description refers to the accompanying drawings.The same reference numbers in different drawings may identify the sameor similar elements. Systems, devices, and/or methods described hereinmay allow for a gas supply system that provides control mechanisms aswell as 100% redundancy to one or more sub-systems within the gas supplysystem. In embodiments, the gas supply system uses one or morehigh-pressure tanks that discharge gas through a gas supply system thatincludes one or more groups of valves, control valves, safety valves,and/or monitor valves that have 100% redundancy with other groups ofvalves, control valves, safety valves, and/or monitor valves. Inembodiments, the gas supply system discharges natural gas to an end-usersystem (e.g., a hospital, natural gas utility, a customer without adirect connection to the pipeline, etc.). In embodiments, the pressurein the one or more tanks may be rated at a maximum pounds per squareinch gauge (PSIG) based on the construction and type of tank that isbeing used and the tank's certification capability for receiving andtransporting a type of gas within the tanks (e.g., natural gas oranother gas, such as nitrogen, hydrogen, biogas, etc.). In embodiments,the natural gas is being delivered at a particular pressure and/or flowrate through the piping system pressure for delivery of gas to anend-user (e.g., a natural gas utility, a commercial user of natural gas,etc.).

In embodiments, one or more pressure gauges may electronically (e.g.,via wireless, satellite, Internet, Intranet systems) send electronicinformation about the gas pressure to one more computing devices thatmonitor the natural gas being distributed within the one or more pipingsections. In embodiments, the one or more computing devices maydetermine, based on the electronic information about pressure, that achangeover is to occur between one or more redundant groups of valves,control valves, safety valves, and/or monitor valves. In embodiments,the one or more types of valves may be manually (e.g., mechanically)controlled and the changeover between different groups of valves,control valves, safety valves, and/or monitor valves is to occurmanually. Additionally and/or alternatively, the one or more types ofvalves may be controlled electronically by one or more computingdevices. In embodiments, the one or more computing devices mayelectronically communicate with one or more valves, control valves,and/or other types of valves to either open or close depending on whichgroups of valves are required. Furthermore, a computing device maydetermine which of one or more tanks (individually or in combination)should provide natural gas into the gas supply system.

Accordingly, a system may allow for (1) distribution of gas from one ormore high-pressure tanks into a gas supply system that includes one ormore piping sections and one or more valves, control valves,non-reversible valves, pressure gauges, temperature gauges, and/or flowrate gages; (2) controlling gas supply within the gas supply system; (3)determining which group of valves should provide distribution andcontrol of gas; (4) lower costs; and (5) 100% redundancy between one setof valves and controller and another set of valves and anothercontroller.

FIG. 1 is a schematic diagram of an example system 100 in which systems,devices, and/or methods described herein may be implemented. As shown inFIG. 1 , system 100 includes tank 101, tank 103, system 102, controller108, controller 110, system 112, system 114, heater 116, system 118, andsystem 120. In embodiments, tanks 101 and 103 may be high-pressure tanksthat contain natural gas. In embodiments, tanks 101 and 103 may eachhold natural gas at a pressure rating of 5,000 PSIG. In this example,systems 112, 114, 118, and 120 are sub-systems of system 100 with eachsub-system including different types of valves (e.g., control valves,fail-close valves, etc.), pressure gauges, and/or flow rate gauges. Inthis example, one or more sub-systems of system 100 may communicateelectronic information (via pressure gauges, flow rate gauges, etc.)about pressure and/or flowrate information to a computing device (e.g.,device 406).

In a non-limiting example, tank 101 is providing natural-gas into system100, which does not contain any natural gas. In this non-limitingexample, tank 101 sends natural gas to both system 102 and system 112.System 112 may include a control valve that prevents natural gas frombeing sent beyond system 112 until a control indicator (e.g., controlgas which provides control pressure information) is received from system102. In embodiments, system 102 may consist of accumulators and valvesthat provide a conditioned gas stream (e.g., gas flowing at a particularpressure) which then provides motive power (e.g., actuate, control,etc.) for valves that are located in other systems. In embodiment,natural gas is delivered to high-pressure (HP) accumulator 102A, fromtank 101. HP accumulator 102A pressure may vary depending upon thepressure within tank 101. Upon exiting HP accumulator 102A, the gaspasses through valves 102B1 and 102B2, reducing the pressure of thenatural-gas down to 200 pounds per square inch (PSIG). At the reducedpressure, the gas enters medium-pressure (MP) accumulator 102E whichprovides secondary storage at a stable pressure. As the gas leaves theMP accumulator 102E, it is further reduced in pressure by a valvelocated between system 102 and controller 108. This further reducedoperating pressure provides the motive power for the valves in the othersystems and is also used as reference pressure information forcontroller 108 to control a control valve. At this point, the controlvalve in system 112 is open and allows natural gas to flow throughsystem 112

In this non-limiting example, based on the communications fromcontroller 108, a control valve in system 112 can be closed (or opened)to manage the downstream pressure within required limits. Accordingly,the control valve in system 112 can be used to reduce the natural gaspressure being delivered from tank 101. If the natural gas pressure isreduced, there may be a drop in temperature of the natural gas. Thus,heater 116 increases the natural gas temperature within the deliveryrange required by the end-user. After passing through the heater 116,the natural gas is sent to system 120.

Additionally, before the natural gas is sent to system 120, a smallproportion of the natural gas is diverted to valve 102D. In thisnon-limiting example, valve 102D reduces the natural gas pressure andreplaces the natural gas that enters system 102 from HP accumulator102A, valve 102B1, and valve 102B2. Thus, valve 102D now sends thenatural gas required to operate controller 108 (which controls a controlvalve in system 112) by providing a reference pressure for controller108 to operate, and also provide gas for the operation of a fail-closevalve. Based on the temperature within system 102, heater 102F (whichmay be a catalytic heater) may operate using natural-gas diverted from apiping section after heater 116.

In addition, natural gas is also sent from a piping section betweenheater 116 and system 120 to provide pressure information to controller108. Based on controller 108 comparing this downstream pressureinformation with the reference pressure information, controller 108 maymake adjustments to the control valve in system 112 to control theamount of gas flow (based on an operator-adjusted set point). If a largesurge of natural gas enters the system and the pressure rises rapidly,due to the control valve in system 112 being too slow to respond, thenthe pressure information will also be sent to another valve withinsystem 102. If the pressure is not within bounds of theoperator-adjusted set point, this other valve within system 102 willstop the flow of gas to the fail-close valve and prevent any additionalnatural gas from entering the system.

In another non-limiting example, tank 103 is providing natural gas intosystem 100, which does not contain any natural gas. In this non-limitingexample, tank 103 sends natural gas to both system 102 and system 114.System 114 may include a control valve that prevents natural-gas frombeing sent beyond system 114 until control gas is received from system102. In embodiments, system 102 may consist of accumulators and valvesthat provide a conditioned gas stream which then provides motive powerfor valves that are located in other systems. In embodiment, natural gasis delivered to high-pressure (HP) accumulator 102A, from tank 103. HPaccumulator 102A pressure may vary depending upon the pressure withintank 101. Upon exiting HP accumulator 102A, the gas pass through valves102C1 and 102C2, reducing the pressure of the natural-gas down to 200pounds per square inch (PSIG). At the reduced pressure, the gas entersMP accumulator 102E and provides secondary storage at a stable pressure.As the gas leaves MP accumulator 102E, it is further reduced in pressureby a valve (not shown) located between system 102 and controller 110.This further reduced operating pressure provides the motive power forthe valves in the other systems and is also used as reference pressureinformation for controller 110 to control a control valve. At thispoint, the control valve in system 114 is open and allows natural gas toflow through system 114.

In this non-limiting example, based on the communications from thecontroller 110, a control valve in system 114 will close to manage thedownstream pressure within the required limits. Accordingly, a controlvalve in system 114 can be used to reduce the natural gas pressure beingdelivered from tank 103. If the natural gas pressure is reduced, theremay be a drop in temperature of the natural gas. Accordingly, heater 116increases the natural gas temperature within the delivery range requiredby the end-user. After passing through the heater 116, the natural gasis sent to system 118.

Additionally, before the natural gas is sent to system 118, a smallproportion of the gas is diverted to valve 102D. In this non-limitingexample, valve 102D reduces the natural gas pressure and replaces thenatural gas that enters system 102 from HP accumulator 102A, valve102C1, and valve 102C2. Thus valve 102D now sends the natural gasrequired to operate controller 110 (which controls a control valve insystem 114) and also provide gas for the operation of the fail-closevalve. Based on the temperature within system 102, heater 102F (whichmay be a catalytic heater) may operate using natural-gas diverted from apiping section after heater 116.

In addition, natural gas is also sent from a piping section betweenheater 116 and system 118 to provide pressure information to controller110. Based on controller 110 comparing this downstream pressureinformation with the reference pressure information, controller 110 maymake adjustments to the control valve in system 114 to control theamount of gas flow (based on an operator-adjusted set point). If a largesurge of natural gas enters the system and the pressure rises rapidly,due to the control valve in system 114 being too slow to respond, thenthe pressure information will also be sent to another valve withinsystem 102. If the pressure is not within bounds of theoperator-adjusted set point, this other valve within system 102 willstop the flow of gas to the fail-close valve and prevent any additionalnatural gas from entering the system.

While the examples use high-pressure tank 101, in the above examples,natural gas can be provided by high-pressure tank 103, or bothhigh-pressure tank 101 and 103.

FIGS. 2A and 2B are example diagrams of a system 200 for distribution ofhigh-pressure gas as well as control systems for the high-pressure gas.FIG. 2A shows a first portion of system 200 and FIG. 2B shows a secondportion of system 200. As shown in FIGS. 2A and 2B diagonal lines (“\\”)are used on piping sections 202, 204, 206, 208, 210, and 252 as they areshown across both FIGS. 2A and 2B. FIGS. 2A and 2B, in combination, showvalves v1, v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12, v13, v14, v15,v16, v17, v18, v19, v20, v21, v22, v23, and v24. In addition, FIG. 2Ashows pipe expansion 239, heater H1 (e.g., a catalytic heater),high-pressure (HP) accumulator tank A1, medium-pressure (MP) accumulatortank A2, pressure safety valve 201, pressure safety valve 203, pressuregauges 212, 213, and 214, controller A, controller B, and pipingsections 202, 204, 206, 207, 208, 209, 210, 211, and 252. FIG. 2A alsoshows valves 217, 219, 221, 223, 225, 227, 229, and 231. Furthermore,FIG. 2B shows piping sections 202, 204, 206, 208, 210, and 252. FIG. 2Balso shows indirect heater 230, burner 232, valve 216, valve 218,pressure safety valve 220, and pressure safety valve 222, flow ratereader 224, and pressure reader 226. In embodiments, any of the valvesdescribed in FIGS. 2A and 2B may be opened and closed either (1)mechanically (e.g., manually), (2) pneumatically, (3) electrically, or(4) electronically based on electronic communications (e.g., wiredand/or wireless from a computing device, such as device 406 described inFIG. 4 ). In FIGS. 2A and 2B, controller A, valves v3, v5, v7, v9, v11,v13, v15, and v17 provide for 100% redundancy of controller B, valvesv4, v6, v8, v10, v12, v14, v16, and v18 (and vice versa). Thus, forexample, if there is a problem with valve v11 (e.g., based on pressurereadings in system 200), then a changeover will be conducted to usecontroller B, valves v4, v6, v8, v10, v12, v14, v16, and v18. Also, forexample, if there is a problem with valve v8 (based on pressure readingsin system 200, a failure of the valve, etc.), then a changeover will beconducted to use controller A, valves v3, v5, v7, v9, v11, v13, v15, andv17. Furthermore, piping sections are shown in FIGS. 2A and 2B that maynot be numbered but may be described based on their location to otherfeatures, such as controllers, valves, pressure gauges, accumulators,pressure safety valves, etc. In embodiments, controller A may be apneumatic, electric, hydraulic, electrohydraulic, or anelectro-pneumatic controller. In embodiments, controller B may be apneumatic, electric, hydraulic, electrohydraulic, or anelectro-pneumatic controller. In embodiments, as shown in FIG. 2A,depending on the type of controller and the type of valve, the linebetween controller A and v7 may be a pneumatic line, hydraulic line,electric line, or any other line that can provide motive power (e.g.,actuate, control, etc.) to v7. In embodiments, as shown in FIG. 2A,depending on the type of controller and the type of valve, the linebetween controller B and v8 may be a pneumatic line, hydraulic line,electric line, or any other line that can provide motive power (e.g.,actuate, control, etc.) to v8. While A1 may be a HP accumulator, A1 inother examples may be any other type of pressure accumulator. While A2may be MP accumulator, A2 in other examples may be any other type ofpressure accumulator.

In a non-limiting example, natural gas is received through v1 from ahigh-pressure tank. In embodiments, v1 (and v2) can be opened manuallyor electronically via electronic communications (e.g., wired,wirelessly, etc.). However, natural gas can also be provided through v2or a combination of two tanks from both v1 and v2. In this non-limitingexample, there is no natural gas in the system until (1) natural gas issent to v3 and/or v4, and (2) natural gas is sent through v1 and passesto high-pressure accumulator tank A1. In embodiments, the pipingdiameter after v1 and v2, and before pipe expansion 239, is smaller thanthe piping diameter of the piping after pipe expansion 239. For example,piping up to pipe expansion 239 (from v1 and v2) may be one inch indiameter while piping after pipe expansion 239 may be two inches indiameter. In embodiments, before any gas enters from any tank into anyof the piping sections, v5 may be closed and v7 may be open. Inembodiments, v5 may be a fail-close valve.

In embodiments, the pressure within tank A1 (a HP accumulator) may varyfollowing the pressure within tanks 101 or 103. In embodiments, tank A1holds a small volume of natural gas to dampen any pressure variationsthat may occur within the mainline (e.g. one or more piping sections).Upon exiting tank A1, the natural gas is then sent to v21 via valve 227and/or v22 via valve 225. As the natural gas passes through v21 and/orv22 the pressure is reduced (e.g., from 1000 PSIG to 200 PSIG) and thenatural gas is sent to tank A2 (a MP accumulator). In embodiments, v21,v22, v23, and H1, may be located in a cabinet 247. In embodiments, tankA2 contains a modest volume (e.g., less than 50 liters) of natural gasto further reduce any effects of pressure variations that may occurwithin the piping sections.

After leaving tank A2, the natural gas then passes through valves 223and 219, the pressure is further reduced to an operating pressure (e.g.,20 PSIG). In addition, the natural gas is delivered via valve 229 topressure gauge 214. In embodiments, the pressure reading by pressuregauge 214 provides information (e.g., viewed locally or sent viaelectronic communications to another device) about whether the amount ofnatural gas in A2 is below a particular threshold level. At any time, inthis or any other non-limiting example, if the pressure information readby pressure gauge 214 is below the particular threshold, this mayindicate that there is not enough natural gas in a high-pressure tankand that the tank should be replaced. A portion of the natural gasexiting valve 219 at the final operating pressure is sent to v20, whichis an inverse acting valve. Since v20 is receiving low-pressureinformation regarding the natural gas, v20 will be fully open. This willallow the natural gas to proceed and pass through v5. At this point, v5(which is a fail-close valve) is opened based on the fully-open positionof v20.

In addition, pressure information (e.g., pressure reference information)of the natural gas exiting tank A2 may be used by controller A (viavalve 223 and then valve 219) to control valve v7 at a later time.However, at this particular time, in this non-limiting example, v7 iscurrently open and allows gas now passing through v5 to continue toflow.

In between v7 and v9, a pressure safety valve 203 is provided to preventa pressure build-up from occurring between v7 and v9. Once the naturalgas passes v9, the natural gas enters piping section 202. The naturalgas flows through piping section 202 and then enter indirect heater 230(e.g., a water bath heater) as shown in FIG. 2B. Within indirect heater230, the natural gas is heated, indirectly, to maintain a temperaturelevel. In embodiments, indirect heater 230 contains water which isheated by burner 232 (e.g., a natural gas burner) and uses the heatedwater via a heat exchange to heat the natural gas as that enters throughpiping section 202.

As shown in FIG. 2A, piping section 252, located after pressure gauge213, may send natural gas to one or more accumulators and valves (notshown in FIG. 2A) which will reduce the natural gas pressure. Thenatural gas with reduced pressure is then transmitted via piping section252 to burner 232 (as shown in FIG. 2B) which then maintains the flamewithin the fire tube (of heater 230) and continues to heat the watercontained in heater 230.

Thus, the natural gas exits indirect heater 230 and enters pipingsection 204. The natural gas passes from piping section 204 into pipingsection 205 (as shown in FIG. 2A), piping section 206 (shown in FIG.2A), and then enters valve vii (as shown in FIG. 2B). The natural gasthen passes through monitor valves v13 and v15. In embodiments, monitorv13 is an inactive monitor valve that is only used if there is a problemwith active monitor valve v15. For example, inactive monitor valve v13may actuate at a pressure level of 55 PSIG while active monitor valvev15 may operate at a pressure level of 50 PSIG. If there is a problemwith v15, then v13 will take over. In embodiments, v13 operates at ahigher pressure and will remain in the open position. If v15 fails, thenthe pressure level will be higher than the required pressure level and,thus, v13 will operate as there is now a higher pressure in that pipingsection. After monitor valve v15, a pressure safety valve 220 isprovided. If there are no problems with pressure, the natural gas passesthrough v17 and passes by pressure safety valve 221. Flow rate reader224 reads the flow amount and device 226 is a pressure gage and pressuretransmitter which sends pressure information to a computing device(e.g., device 406) to determine whether a sufficient amount of naturalgas is being delivered to gas system 240 (e.g., an end-user system oranother system).

In this non-limiting example, when natural gas enters piping section205, the natural gas may also follow piping section 207 and then pipingsection 209. The natural gas entering piping section 209 is sent toheater H1 (via valve 231) and valve v23. The natural gas sent to v23 isthen sent to mid-pressure accumulator tank A2. This natural gas is thenused to provide reference pressure information to controller A. Thus,controller A no longer requires natural gas (and the natural gaspressure information) via A1, V21 and/or V22 which are only used toprovide the initial pressure needed for controller A to operate thefirst time. In this non-limiting example, the natural gas pressureexiting v23 is at a higher pressure than the natural gas that is exitingv21 and/or v22 from high-pressure accumulator A1. Thus, the pressurefrom v23 back-pressurizes and prevents gas from v21 and/or v22 fromproceeding any further. Thus, the gas passes from v23 and then entersmid-pressure accumulator A2.

In addition, the natural gas that enters piping section 207 also enterspiping section 211. The gas from piping section 211 goes to v20 andprovides gas pressure information to v20. If this pressure (provided inthe gas pressure information) is above a prescribed level (e.g., anoperator adjustable set point), v20 will close and shut off the naturalgas required to operate v5 (as v5 is a fail-close valve). Thus, v5 willclose and prevent the pressure within the pipeline increasing beyondthis prescribed level and may also prevent any safety valves fromopening and allowing natural gas to be emitted to the atmosphere.

In this non-limiting example, when gas enters v11, a portion of gas issent through valve 216 and natural gas is sent through piping section208 to controller A. In this non-limiting example, controller A receivesdownstream natural gas pressure information from the natural gas sentthrough piping section 208. Based on comparing downstream natural gaspressure information with the reference pressure information (receivedvia valve 219), controller A controls v7 to determine how much naturalgas (as long as natural gas is flowing through v5) should flow throughv7.

In another non-limiting example, natural gas is received through v1 froma high-pressure tank. In embodiments, v1 (and v2) can be opened manuallyor electronically via electronic communications (e.g., wired,wirelessly, etc.). However, natural gas can also be provided through v2or a combination of two tanks from both v1 and v2. In this non-limitingexample, there is no natural gas in the system until (1) natural gas issent to v3 and/or v4, and (2) natural gas is sent through v1 and passesto high-pressure accumulator tank A1. In embodiments, the pipingdiameter after v1 and v2, and before pipe expansion 239, is smaller thanthe piping diameter of the piping after piping expansion 239. Forexample, piping up to pipe expansion 239 (from v1 and v2) may be oneinch in diameter while piping after pipe expansion 239 may be two inchesin diameter.

In embodiments, the pressure within tank A1 (a HP accumulator) may varyfollowing the pressure within tanks 101 or 103. In embodiments, tank A1holds a small volume to natural gas to dampen any pressure variationsthat may occur within the mainline (e.g., one or more piping sections).Upon exiting tank A1, the natural gas is then sent to v21 via valve 227and/or v22 via valve 225. As the natural gas passes through v21 and/orv22 the pressure is reduced (e.g., from 1000PSIG to 200 PSIG) and thenatural gas is sent to tank A2 (a MP accumulator). In embodiments, tankA2 contains a modest volume (e.g., less than 50 liters) of natural gasto further reduce any effects of pressure variations that may occurwithin the piping sections.

After leaving tank A2, the natural gas then passes through valves 221and 217, the pressure is further reduced to an operating pressure (e.g.,20 PSIG). In addition, the natural gas is delivered via valve 229 topressure gauge 214. A portion of the natural gas exiting valve 217 atthe final operating pressure is sent to v19, which is an inverse actingvalve. Since v19 is receiving a low-pressure communication (e.g., gaspressure information) from the mainline (e.g., one or more pipingsections), v19 will be fully open. This will allow the natural gas toproceed and pass through v6. At this point, v6 (which is a fail-closevalve) is opened based on the fully-open position of v19.

In addition, pressure information (e.g., pressure reference information)of natural gas exiting tank A2 may be used by controller B (via valve221 and then valve 217) to control valve v8 at a later time. However, atthis particular time, in this non-limiting example, v8 is currently openand allows gas now passing through v6 to continue to flow.

In between v8 and v10, a pressure safety valve 201 is provided toprevent a pressure build-up from occurring between v8 and v10. Once thenatural gas passes v10, the natural gas enters piping section 202. Thenatural gas then flows through piping section 202 and then entersindirect heater 230 (e.g., a water bath heater) as shown in FIG. 2B.Within indirect heater 230, the natural gas is heated, indirectly, tomaintain a temperature level. In embodiments, indirect heater 230contains water which is heated by burner 232 (e.g., a natural gasburner) and uses the heated water via a heat exchange to heat thenatural gas as that enters through piping section 202.

As shown in FIG. 2A, piping section 252, located after pressure gauge213, may send natural gas to one or more accumulators and valves (notshown in FIG. 2A) which will reduce the natural gas pressure. Thenatural gas with reduced pressure is then transmitted via piping section252 to burner 232 (as shown in FIG. 2B) which then maintains the flamewithin the fire tube (of heater 230) and continues to heat the watercontained in heater 230.

Thus, the natural gas exits indirect heater 230 and enters pipingsection 204. The natural gas passes from piping section 204 into pipingsection 205 (as shown in FIG. 2A), piping section 206 (shown in FIG.2A), and then enters valve v12 (as shown in FIG. 2B). The natural gasthen passes through monitor valves v14 and v16. In embodiments, monitorv14 is an inactive monitor valve that is only used if there is a problemwith active monitor valve v16. For example, inactive monitor valve v14may actuate at a pressure level of 55 PSIG while active monitor valvev16 may operate at a pressure level of 50 PSIG. If there is a problemwith v16, then v14 will take over. In embodiments, v14 operates at ahigher pressure and will remain in the open position. If v16 fails, thenthe pressure level will be higher than the required pressure level and,thus, v14 will operate as there is now a higher pressure in that pipingsection. After monitor valve v16, a pressure safety valve 222 isprovided. If there are no problems with pressure, the natural gas passesthrough v18 and then passes by pressure safety valve 221. Flow ratereader 224 reads the flow amount and device 226 is a pressure gage andpressure transmitter which sends pressure information to a computingdevice (e.g., device 406) to determine the amount of natural gas beingdelivered to gas system 240.

In this non-limiting example, when natural gas enters piping section205, the natural gas may also follow piping section 207 and then pipingsection 209. The natural gas entering piping section 209 is sent toheater H1 (via valve 231) and valve v23. The natural gas sent to v23 isthen sent to mid-pressure accumulator tank A2. The natural gas sent tov23 is then sent to mid-pressure accumulator tank A2. This natural gasis then used to provide reference pressure information to controller B.Thus, controller B no longer requires natural gas (and natural gaspressure information) via A1, V21 and/or V22 which are only used toprovide the initial pressure needed for controller B to operate thefirst time. In this non-limiting example, the natural gas pressureexiting v23 is at a higher pressure than the natural gas that is exitingv21 and/or v22 from high-pressure accumulator A1. Thus, the pressurefrom v23 back-pressurizes and prevents gas from v21 and/or v22 fromproceeding any further. Thus, the gas passes from v23 and then entersmid-pressure accumulator A2.

In addition, the natural gas that enters piping section 207, and goes tov19, provides gas pressure information to v19. If this pressure value(provided in the gas pressure information) is above a prescribed level(e.g., an operator adjustable set point) v19 will close and shut off thenatural gas required to operate v6 (as v6 is a fail-close valve). Thus,v6 will close and prevent the pressure within the pipeline increasingbeyond this prescribed level and may also prevent any safety valves fromopening and allowing natural gas to be emitted to the atmosphere.

In this non-limiting example, when gas enters v12, a portion of gas issent through valve 218 and natural gas is sent through piping section210 to controller B. In this non-limiting example, controller B receivesdownstream natural gas pressure information from the natural gas sentthrough piping section 210. Based on comparing downstream natural gaspressure information with the reference pressure information (receivedvia valve 217), controller B controls v8 to determine how much naturalgas (as long as natural gas is flowing through v6) should flow throughv8.

In embodiments, for FIGS. 2A and 2B, device 406 (described in FIG. 4 )may in communication with system 200 (e.g., system 404 described in FIG.4 ). In embodiments, device 406 may receive electronic information aboutpressure readings in system 200 and generate messages to switch overfrom one set of valves to another set of valves in the event of problemsoccurring within the system. For example, if there is a problem withvalve v4 (based on pressure readings in system 200, a failure of thevalve, etc.), then device 406 may receive information about the problem(e.g., pressure reading information) and generate a message to conduct achangeover and use valves v3, v5, v7 and v9, and controller A. Inembodiments, the messages may be sent to one or more valves in system200 which are used to open or close the valves. Additionally, oralternatively, the messages may be sent to a user of system 200 who maychange one or more valves in system 200 manually (e.g., mechanically).In embodiments, device 406 may be associated with a graphical userinterface that includes a visual display. In embodiments, device 406 maybe associated with a control panel system that includes alarms, warninglights, and/or other lighting indicators that are may be incorporated aspart of the graphical user interface or are part of an analog system.Thus, a user may use the graphical user interface to view various typesof information that are used to make decisions as to whether one or morevalves should be opened or closed. In embodiments, based on changingrequirements (e.g., pressure requirements) of natural gas supply ofsystem 200 to an end-user, a set point for a controller (e.g.,controller A, controller B, etc.) may be adjusted (e.g., electronically,manually, etc.) to accommodate any such updates. In embodiments, the setpoint value may be based on reference pressure information, arelationship between the reference pressure information and thedownstream pressure information, or another value. In embodiments, acontroller may adjust a control valve (e.g., v7) based on comparing theset point to (i) a value based on a relationship (e.g., differential,proportional, etc.) between reference pressure information anddownstream pressure information, (ii) a value based on downstreampressure information, (iii) a value based on reference pressureinformation, or (iv) another value (e.g., end-user pressurerequirements). For the examples described above for systems 100 and 200,in embodiments, a set point value for v19 may be less than, equal to, orgreater than a set point value for controller A. Also, in embodiments, aset point value for v20 may be less than, equal to, or greater than sset point value for controller B. In embodiments, any set point may beadjusted based on gas pressure requirements of an end-user system. Forthe non-limiting examples described in FIG. 2 , gas refers to naturalgas. However, in other examples, other types of gases may be used, suchas biogas, oxygen, reclaimed natural gas, or any other type of gas.

FIG. 3 is an example flow chart diagram of an example process 300. Inembodiments, example process 300 may be performed by a controller (e.g.,controller 108, 110, controller A, and/or controller B, as described inFIGS. 1, 2A, and 2B), device 406 and/or electronic application 408(which are described in FIG. 4 ). In embodiments, example 300 may beconducted to control one or more valves within a system, such as system100 and/or system 200. As shown in FIG. 3 , at step 302, a controllermay receive natural gas. In embodiments, the controller may receive thenatural gas from a MP accumulator and a set of valves (e.g., v21 andv22). In embodiments, the controller may be controller A, controller B,controller 108, and/or controller 110. By receiving the gas pressureinformation of the natural gas (which is at a particular pressure thatis the minimum pressure level that the controller may operate at), thecontroller, at step 304, maintains a control valve as open. Inembodiments, the control valve may be a fail-open valve. In alternateembodiments, the control valve may be another type of valve. At step306, the controller receives downstream pressure information (of thenatural gas that is downstream of the controller). In embodiments, thepressure information may be associated with natural gas that isdownstream of the control valve. At step 308, the controller receivesadditional natural gas (which includes reference pressure information)for its controlling mechanism (e.g., controlling a control valve). Inembodiments, the additional natural gas is received via MP accumulatorand another valve (e.g., v23). In embodiments, the MP accumulator andthe other valve reduces the pressure of natural gas downstream of thecontroller and this reduced pressure natural gas is the additionalnatural gas then sent to the controller. At step 310, the controllerchange the control valve and determine whether it should change theamount of natural gas passing through the control valve. In embodiments,the controller makes this determination based on the downstream pressureinformation received in step 306 and the pressure reference informationreceived in step 308. If the downstream pressure is below a particularthreshold pressure level, then no changes are made to the control valve(NO) and the control valve is kept fully open (step 304). If thedownstream pressure is above the particular threshold pressure level,then changes are made to the control valve (YES) at step 312. Thus, thecontroller partially (or fully) closes the control valve to reduce theamount of natural gas being sent downstream.

FIG. 4 is a diagram of example environment 400 in which systems,devices, and/or methods described herein may be implemented. FIG. 4shows network 402, system 404, device 406, and application 408.

Network 402 may include a local area network (LAN), wide area network(WAN), a metropolitan network (MAN), a telephone network (e.g., thePublic Switched Telephone Network (PSTN)), a Wireless Local AreaNetworking (WLAN), a WiFi, a hotspot, a Light Fidelity (LiFi), aWorldwide Interoperability for Microware Access (WiMax), an ad hocnetwork, an intranet, the Internet, a satellite network, a GPS network,a fiber optic-based network, and/or combination of these or other typesof networks. Additionally, or network 402 may include a cellularnetwork, a public land mobile network (PLMN), a second-generation (2G)network, a third-generation (3G) network, a fourth-generation (4G)network, a fifth-generation (5G) network, and/or another network. Inembodiments, network 402 may allow for devices describe any of thedescribed figures to electronically communicate (e.g., using emails,electronic signals, URL links, web links, electronic bits, fiber opticsignals, wireless signals, wired signals, etc.) with each other to sendand receive various types of electronic communications.

System 404 (e.g., system 100, system 200 as described above) may includeone or more devices that can communicate and/or receive electronicinformation to/from device 406, and/or application 408, via network 402.In embodiments, system 404 may include valves, control valves, monitorvalves, and/or heaters which may send/receive electronic informationto/from device 406 (and/or application 408) to turn on or off differentvalves in system 404. In embodiments, system 404 may include sensorsand/or gauges that communicate electronic information about pressure,temperature, and/or flow rates to device 406 and/or application 408 vianetwork 402. In embodiments, system 404 may be system 100 and system200. In embodiments, system 404 may be placed on moving device 410(e.g., using a truck, tractor, type of boat, etc.) that can move or bemoved from one location to another location. In alternate embodiments,moving device 410 may be a part of system 404. In embodiments, otherthan electrical power to communications devices (e.g., pressure gaugesthat can electronically communicate information) that are part of system404, no other electrical power may be used to control any of the valvesin system 404 (e.g., all valves may be pneumatically and/or mechanicallycontrolled). In alternate embodiments, system 404 may be powered byelectrical power, solar power, and/or other type of power. Inembodiments, system 404 may be located at remote locations and bepowered by its own power system which may be a generator system (e.g.,operating on natural gas, diesel, etc.), and/or a solar-powered panelsystem which generates power that is used by one or more of the portionsof system 404 in conjunction with other portions of system 404 that mayrequire pneumatic power and/or no type of power (e.g., manuallycontrolled valves).

Device 406 may include any computation or communications device that iscapable of communicating with a network (e.g., network 402) with otherdevice and/or systems, such as system 404. For example, device 406 mayinclude a computing device, radiotelephone, a personal communicationssystem (PCS) terminal (e.g., that may combine a cellular radiotelephonewith data processing and data communications capabilities), a personaldigital assistant (PDA) (e.g., that can include a radiotelephone, apager, Internet/intranet access, etc.), a smartphone, a desktopcomputer, a laptop computer, a tablet computer, a camera, a digitalwatch, a digital glass, or another type of computation or communicationsdevice.

Device 406 may receive and/or display content. The content may includeobjects, data, images, audio, video, text, files, and/or links to filesaccessible via one or more networks. Content may include a media stream,which may refer to a stream of content that includes video content(e.g., a video stream), audio content (e.g., an audio stream), and/ortextual content (e.g., a textual stream). In embodiments, an electronicapplication may use an electronic graphical user interface to displaycontent and/or information via user device 406. Device 406 may have atouch screen and/or a keyboard that allows a user to electronicallyinteract with an electronic application. In embodiments, a user mayswipe, press, or touch device 406 in such a manner that one or moreelectronic actions will be initiated by device 406 via an electronicapplication.

Device 406 may include a variety of applications, such as, for example,a gas analyzer application, a flow rate application, a temperatureapplication, a composition analyzer application, an e-mail application,a telephone application, a camera application, a video application, amulti-media application, a music player application, a visual voice mailapplication, a contacts application, a data organizer application, acalendar application, an instant messaging application, a textingapplication, a web browsing application, a blogging application, and/orother types of applications that are a combination of two or more of theabove applications (e.g., electronic application 408).

Electronic application 408 may be capable of interacting with device 406and/or system 404 to automatically and electronically receive electronicinformation for one or more persons. In embodiments, electronicapplication 408 may obtain electronic information about pressure,temperature, and/or flow rates associated with natural gas. Inembodiments, electronic application 408 may be associated with agraphical user interface that may display images, generate sounds,and/or display information associated with system 404.

FIG. 5 is a diagram of example components of system 504 and device 506.Device 500 may correspond to computing devices, such as device 406,and/or a computing device feature that is part of systems 100 and 200.

As shown in FIG. 5 , device 500 may include a bus 510, a processor 520,a memory 530, an input component 540, an output component 550, and acommunications interface 560. In other implementations, device 500 maycontain fewer components, additional components, different components,or differently arranged components than depicted in FIG. 5 .Additionally, or one or more components of device 500 may perform one ormore tasks described as being performed by one or more other componentsof device 500.

Bus 510 may include a path that permits communications among thecomponents of device 500. Processor 520 may include one or moreprocessors, microprocessors, or processing logic (e.g., afield-programmable gate array (FPGA) or an application-specificintegrated circuit (ASIC)) that interprets and executes instructions.Memory 530 may include any type of dynamic storage device that storesinformation and instructions, for execution by processor 520, and/or anytype of non-volatile storage device that stores information for use byprocessor 520.

Input component 540 may include a mechanism that permits a user to inputinformation to device 500, such as a keyboard, a keypad, a button, aswitch, etc. Output component 550 may include a mechanism that outputsinformation to the user, such as a display, a speaker, one or morelight-emitting diodes (LEDs), etc.

Communications interface 560 may include any transceiver-like mechanismthat enables device 500 to communicate with other devices and/orsystems. For example, communications interface 560 may include anEthernet interface, an optical interface, a coaxial interface, awireless interface, or the like.

In another implementation, communications interface 560 may include, forexample, a transmitter that may convert baseband signals from processor520 to radiofrequency (RF) signals and/or a receiver that may convert RFsignals to baseband signals. Alternatively, communications interface 560may include a transceiver to perform functions of both a transmitter anda receiver of wireless communications (e.g., radiofrequency, infrared,visual optics, etc.), wired communications (e.g., conductive wire,twisted pair cable, coaxial cable, transmission line, fiber optic cable,waveguide, etc.), or a combination of wireless and wired communications.

Communications interface 560 may connect to an antenna assembly (notshown in FIG. 5 ) for transmission and/or reception of the RF signals.The antenna assembly may include one or more antennas to transmit and/orreceive RF signals over the air. The antenna assembly may, for example,receive RF signals from communications interface 560 and transmit the RFsignals over the air, and receive RF signals over the air and providethe RF signals to communications interface 560. In one implementation,for example, communications interface 560 may communicate with a network(e.g., wireless network, Internet, Intranet, etc.).

As will be described in detail below, device 500 may perform certainoperations. Device 500 may perform these operations in response toprocessor 520 executing software instructions (e.g., a computerprogram(s)) contained in a computer-readable medium, such as memory 530,a secondary storage device (e.g., hard disk, CD-ROM, etc.), or otherforms of RAM or ROM. A computer-readable medium may be defined as anon-transitory memory device. A memory device may include space within asingle physical memory device or spread across multiple physical memorydevices. The software instructions may be read into memory 530 fromanother computer-readable medium or another device. The softwareinstructions contained in memory 530 may cause processor 520 to performprocesses described herein. Alternatively, hardwired circuitry may beused in place of or in combination with software instructions toimplement processes described herein. Thus, implementations describedherein are not limited to any specific combination of hardware circuitryand software.

In the preceding specification, gas may be interchangeably used withnatural gas. While natural gas is used in the examples described in thepreceding specification, any of the systems described in FIGS. 1, 2A,and 2B, may use other types of gases, such as biogas, oxygen, reclaimednatural gas, or any other type of gas. Furthermore, in the precedingspecification, a high-pressure tank may be a type of tank, vessel,storage device, or any other container that contains gas. In thepreceding specification, as shown in FIGS. 1, 2A, and 2B, each of thevalves, pressure readers, flow rate readers, and/or temperature readers,may receive or send electronic information via wired or wirelesscommunications to a computing device (e.g., device 406).

While various actions are described as selecting, displaying,transferring, sending, receiving, generating, notifying, and storing, itwill be understood that these example actions are occurring within anelectronic computing and/or electronic networking environment and mayrequire one or more computing devices, as described in FIG. 2 , tocomplete such actions. Also it will be understood that any of thevarious actions can result in any type of electronic information to bedisplayed in real-time and/or simultaneously on multiple user devices(e.g., similar to user device 212). For FIG. 3 , the order of the blocksmay be modified in other implementations. Further, non-dependent blocksmay be performed in parallel.

In the preceding specification, a high-pressure accumulator (e.g., A1 inFIG. 2A) and a mid-pressure accumulator may be an American Society ofMechanical Engineers (ASME) certified expansion tank (e.g., bladdertank, diaphragm tank, etc.). In the preceding specification, acontroller (e.g., controller 108, controller 110, controller A,controller B) may be a controller that can compare sensed processpressure (or differential pressure) with an operator-adjusted set point,and send a pneumatic signal to an adjacent control element (e.g.,control valve v7) that maintains the process pressure at or near the setpoint value. In embodiments, a controller may be proportional only,proportional plus reset, differential gap, or any other type ofconfiguration. In the preceding specification, a control valve (e.g., v7and v8) may be a type of globe valve may be controlled pneumatically,electrically, and/or electronically. In the preceding specification,valves (e.g., v3) may be a type of ball valve. In the precedingspecification, safety valves may be a type of relief valve (e.g.,threaded or flanged valve). In the preceding specification, a fail-closevalve (e.g., v5) may be a stem guided and/or non-balanced valve. Inembodiments, monitor valves (e.g., v14, v16, etc.) may be a type ofrotary ball type valve or any other type of valve.

In the preceding specification, various preferred embodiments have beendescribed with reference to the accompanying drawings. It will, however,be evident that various modifications and changes may be made thereto,and additional embodiments may be implemented, without departing fromthe broader scope of the invention as set forth in the claims thatfollow. The specification and drawings are accordingly to be regarded inan illustrative rather than restrictive sense.

What is claimed is:
 1. An apparatus, comprising: a first valve (v1),wherein the apparatus is configured to receive a first amount of naturalgas through the first valve (v1); a first piping section; ahigh-pressure accumulator (A1), wherein the first piping section isbetween the first valve (v1) and the high-pressure accumulator (A1); asecond valve (225); a catalytic heater (H1); a medium-pressureaccumulator (A2), wherein the catalytic heater (H1) is located betweenthe high-pressure accumulator (A1) and the mid-pressure accumulator(A2); a first controller (A), wherein the first controller (A) isconfigured to be connected to the mid-pressure accumulator (A2) via asecond piping section; a control valve (v7), wherein the firstcontroller (A) is configured use the first amount of natural gas tocontrol the control valve (v7); a third piping section; a fail-closevalve (v5), wherein the third piping section is between the firstcontroller (A) and the fail-close valve (v5); a fourth piping section,wherein the fail-close valve (v5) and the control valve (v7) are locatedon the fourth piping section; a fifth piping section (202); an indirectheater (230), wherein the fifth piping section (202) is located betweenthe control valve (v7) and the indirect heater (230); a sixth pipingsection (204); a seventh piping section (207), wherein the sixth pipingsection (204) is configured to be connected to the seventh pipingsection (207); an inverse acting valve (v20), wherein the seventh pipingsection (207) is configured to be connected to the inverse acting valve(v20), and wherein the third piping section is connected to the inverseacting valve (v20); an eighth piping section (209), wherein the eighthpiping section (209) is configured to be connected to the seventh pipingsection (207); a third valve (v23), wherein the eighth piping section(209) is configured to be connected to the third valve (v23); and aninth piping section, wherein the ninth piping section is configured tobe connected between the third valve (v23) and the mid-pressureaccumulator (A2), wherein the mid-pressure accumulator (A2) isconfigured to send a second amount of natural gas, from the mid-pressureaccumulator (A2), through the ninth piping section, to the firstcontroller (A), and wherein the first controller (A) is configured touse the second amount of natural gas to control the control valve (v7)instead of the first amount of natural gas based on the second amount ofnatural gas having a greater pressure than the first amount of naturalgas.
 2. The apparatus of claim 1, wherein the heater is an indirectheater and is located after the first controller (A).
 3. The apparatusof claim 1, further comprising: a computing device; and multiple safetyvalves.
 4. The apparatus of claim 1, further comprising: a secondcontroller (B); another fail-close valve (v6), wherein the otherfail-close valve (v6) is located before the control valve on a tenthpiping section.
 5. The apparatus of claim 1, wherein the firstcontroller(A) does not control the fail-close valve.
 6. The apparatus ofclaim 1, further comprising: a burner, wherein the burner is located:after the control valve (v7), and before the indirect heater (230). 7.The apparatus of claim 1, wherein the apparatus is moveable.
 8. Adevice, comprising: a memory; a processor coupled to the memory to:receive electronic information about pressure; and generate electronicinstructions to open or close one or more valves, wherein the one ormore valves include a control valve and a fail-close valve; a firstvalve (v1), wherein the apparatus is configured to receive a firstamount of natural gas through the first valve (v1); a first pipingsystem; a high-pressure accumulator (A1), wherein the first pipingsection is between the first valve (v1) and the high-pressureaccumulator (A1); a second valve (225); a catalytic heater (H1); amedium-pressure accumulator (A2), wherein the catalytic heater (H1) islocated between the high-pressure accumulator (Al) and the mid-pressureaccumulator (A2); a first controller (A), wherein the first controller(A) is configured to be connected to the mid-pressure accumulator (A2)via a second piping section; a control valve (v7), wherein the firstcontroller (A) is configured use the first amount of natural gas tocontrol the control valve (v7); a third piping section; a fail-closevalve (v5), wherein the third piping section is between the firstcontroller (A) and the fail-close valve (v5); a fourth piping section,wherein the fail-close valve (v5) and the control valve (v7) areconfigured to be attached on the fourth piping section; a fifth pipingsection (202); an indirect heater (230), wherein the fifth pipingsection (202) is between the control valve (v7) and the indirect heater(230); a sixth piping section (204); a seventh piping section (207),wherein the sixth piping section (204) is configured to be connected tothe seventh piping section (207); an inverse acting valve (v20), whereinthe seventh piping section (207) is configured to be connected to theinverse acting valve (v20), and wherein the third piping section isconfigured to be connected to the inverse acting valve (v20); an eighthpiping section (209), wherein the eighth piping section (209) isconfigured to be connected to the seventh piping section (207); a thirdvalve (v23), wherein the eighth piping section (209) is configured to beconnected to the third valve (v23); and a ninth piping section, whereinthe ninth piping section is configured to be connected between the thirdvalve (v23) and the mid-pressure accumulator (A2), wherein themid-pressure accumulator (A2) is configured to send a second amount ofnatural gas, from the mid-pressure accumulator (A2), through the ninthpiping section, to the first controller (A), and wherein the firstcontroller (A) is configured to use the second amount of natural gas tocontrol the control valve (v7) instead of the first amount of naturalgas based on the second amount of natural gas having a greater pressurethan the first amount of natural gas.
 9. The device of claim 8, whereinthe first controller (A) pneumatically controls the control valve (v7).10. The device of claim 8, wherein the first controller (A) does notcontrol the fail-close valve (v5).
 11. The device of claim 8, whereinthe electronic instructions are displayed on a graphical user interface,and wherein the device controls the graphical user interface.
 12. Thedevice of claim 8, wherein the fail-close valve (v5) is located beforethe control valve (v7), and the device further comprising: a secondcontroller (B) .
 13. A method, comprising: receiving, by a natural gascontrol system, a first amount of natural gas, wherein the natural gascontrol system includes: a first valve (v1), wherein the apparatus isconfigured to receive the first amount of natural gas through the firstvalve (v1); a first piping system; a high-pressure accumulator (Al),wherein the first piping section is between the first valve (v1) and thehigh-pressure accumulator (A1); a second valve (225); a catalytic heater(H1); a medium-pressure accumulator (A2), wherein the catalytic heater(H1) is located between the high-pressure accumulator (A1) and themid-pressure accumulator (A2); a first controller (A), wherein the firstcontroller (A) is connected to the mid-pressure accumulator (A2) via asecond piping section; a control valve (v7), wherein the firstcontroller (A) is configured use the first amount of natural gas tocontrol the control valve (v7); a third piping section; a fail-closevalve (v5), wherein the third piping section is between the firstcontroller (A) and the fail-close valve (v5); a fourth piping section,wherein the fail-close valve (v5) and the control valve (v7) are locatedon the fourth piping section; a fifth piping section (202); an indirectheater (230), wherein the fifth piping section (202) is located betweenthe control valve (v7) and the indirect heater (230); a sixth pipingsection (204); a seventh piping section (207), wherein the sixth pipingsection (204) is connected to the seventh piping section (207); aninverse acting valve (v20), wherein the seventh piping section (207) isconnected to the inverse acting valve (v20), and wherein the thirdpiping section is connected to the inverse acting valve (v20); an eighthpiping section (209), wherein the eighth piping section (209) isconnected to the seventh piping section (207); a third valve (v23),wherein the eighth piping section (209) is connected to the third valve(v23); and a ninth piping section, wherein the ninth piping section isconnected between the third valve (v23) and the mid-pressure accumulator(A2), sending, by the natural gas control system, the first amount ofnatural gas to the high-pressure accumulator (A1); heating, by thenatural gas control system, the first amount of natural gas after thefirst amount of natural gas is sent through the high-pressureaccumulator (A1); sending, by the natural gas control system, the firstamount of natural gas to the mid-pressure accumulator (A2); sending, bythe natural gas control system, the first amount of natural gas to thefirst controller (A) and to the fail-close valve (v5) after the naturalgas is sent to the mid-pressure accumulator (A2); sending, by thenatural gas control system, the first amount of natural gas to theindirect heater (230); heating, by the natural gas control system, thefirst amount of natural gas; sending, by the natural gas control system,the first amount of natural gas out of the indirect heater (230);sending, by the natural gas control system, a second amount of naturalgas to the third valve (v23); heating, by the natural gas controlsystem, the second amount of natural gas after the second amount ofnatural gas exits the third valve (v23); sending, by the natural gascontrol system, the second amount of natural gas to the mid-pressureaccumulator (A2); and sending, by the natural gas control system, thesecond amount of natural gas to the first controller (A), wherein thesecond amount of natural gas is at a higher pressure than the firstamount of natural gas and prevents the first amount of natural gas,exiting the second valve (225), from being sent to the mid-pressureaccumulator (A2).
 14. The method of claim 13, wherein the firstcontroller (A) pneumatically controls the first amount of natural gas.15. The method of claim 13, wherein the first controller (A) is notconnected to the first piping section.
 16. The apparatus of claim 1,further comprising: a second controller (B), wherein the secondcontroller (B) is configured to be connected to the mid-pressureaccumulator (A2) via an eleventh piping section; another control valve(v8) and another fail-close valve (v6), wherein the other control valve(v8) and the other fail-close valve (v6) are located on a twelfth pipingsection; and a thirteenth piping section, wherein the thirteenth pipingsection is between the second controller (B) and the fail-close valve(v5), and wherein the thirteenth piping section is configured to beconnected to the fifth piping section (202).
 17. The apparatus of claim16, further comprising: a fourth valve (v11), wherein the fourth valve(v11) is located after the indirect heater (230); a fifth valve (218), asixth valve (v13), wherein the fifth valve (218) is located between thefourth valve (vii) and the sixth valve (v13), and wherein the fifthvalve (218) is located a fourteenth piping section (208), wherein thefourteenth piping section (208) is located between the fifth valve (218)and the first controller (A).
 18. The method of claim 13, furthercomprising: sending, by the natural gas control system, a third amountof natural gas to the inverse acting valve (v20); sending, by thenatural gas control system, a fourth amount of natural gas to a fourthvalve (v11), wherein the fourth amount of natural gas is sent to anothernatural gas system; sending, by the natural gas control system, a fifthamount of natural gas to the first controller (A); and using, by thenatural gas control system, the fifth amount of natural gas and thesecond amount of natural gas to determine how the first controller Acontrols the control valve (v7).
 19. The method of claim 13, furthercomprising: a second controller (B), wherein the second controller (B)is connected to the mid-pressure accumulator (A2) via an eleventh pipingsection; another control valve (v8) and another fail-close valve (v6),wherein the other control valve (v8) and the other fail-close valve (v6)are located on a twelfth piping section; and a thirteenth pipingsection, wherein the thirteenth piping section is between the secondcontroller (B) and the fail-close valve (v5), and wherein the thirteenthpiping section is connected to the fifth piping section (202).
 20. Themethod of claim 19, further comprising: a fourth valve (v11), whereinthe fourth valve (v11) is located after the indirect heater (230); afifth valve (218), a sixth valve (v13), wherein the fifth valve (218) islocated between the fourth valve (vii) and the sixth valve (v13), andwherein the fifth valve (218) is located a fourteenth piping section(208), wherein the fourteenth piping section (208) is located betweenthe fifth valve (218) and the first controller (A).